1. Field
The present invention relates generally to communication systems, and more specifically to detection of a Wireless Local Access Network (WLAN) by a mobile station in a cellular communication system.
2. Background
Wireless Local Access Networks (WLANs) provide wireless access to a communication network within a local geographical area, such as a building or in a cybercafe. WLANs are currently considered by many cellular carriers to alleviate loading of a cellular system, so as to increase capacity. Additionally, users desire access to local WLANs to enhance reception and data rates of communications through a wireless device. A problem exists in detecting and selecting WLAN systems. The purpose of system detection is to detect the availability of a wireless access medium (e.g., cdma2000, WLAN, etc.). The purpose of system selection is to select an access medium for transporting application contents. System selection may be based on the availability of access media, preference policy, application status, user intervention, etc., or a combination thereof.
Typically, a cellular system transmits a paging indicator periodically to page a mobile station when there is a pending communication. Similarly, a WLAN may be advertised by a beacon transmitted by the WLAN. Both the paging indicator and the beacon require the mobile station to scan for the transmitted signal. As the mobile station often has little information as to the location and accessibility of a WLAN, the mobile station may scan for the WLAN periodically expending considerable power. There is a need therefore for an efficient, accurate method of system detection and selection.